The present invocation relates to a profile system for measuring a profile of a strip of continuously moving material produced by a mill.
In typical mill systems, a strip of material is produced in a continuously moving manner. For quality control, the profile of the material needs to be measured from edge to edge of the strip. Typically, the thickness measurement used to develop the profile is performed without contact with the material, but this measurement can also be done with a gauge contact For example, the measurement of thickness can be made by a beam of radiation, by measurement of backscatter radiation, ultrasonic, or absorption of radiation.
As the product is moving longitudinally through the mill, a gauge moving transversely across the strip will not give a true profile measurement of the thickness across the strip, but rather a long, longitudinal cross cut. To obviate this problem, a system in common use, in particular in steel hot strip mills, uses two gauges. Such a system is shown in FIG. 1. A first gauge remains stationary in the center of the strip, while a second gauge is moved transversely. The readings of the two gauges are plotted as a function of transversal distance. In this manner, longitudinal variations in the strip thickness are not taken into account. Only transversal variations are represented. Since each gauge can cost in the hundreds of thousands of dollars, the problem with this system is that it is expensive due to the need for two gauges.
Another problem represented by these two gauges is the problem of size. Each of the gauges is relatively large. In some applications, such as a reversing mill. there is a relatively small space requirement between a mill stand and a coiler box to keep the coil hot during the rolling process. The coffer box is placed as close as possible to the mill stand so that the metal remains hot. Using two gauges to provide a thickness measurement undesirably lengthens the distance between the furnace and the mill stand.
Another known gauge that measures the profile of a strip uses a single gauge that is stationary, but does not measure the thickness of the strip material in a punctual manner.
Instead, the single gauge uses a plurality of scattering radiation emitters and sensors to provide a spread of radiation across the entire width of the strip. However, because the material is moving rapidly through the mill and the gauge, this method provides only an averaging of the profile over a relatively large area of the strip. It is therefore not as accurate as scanning performed in a punctual manner.
There is thus a need for a system and a method for measuring the profile of a strip of continuously moving material using a single gauge to measure the thickness of the strip in a punctual manner.
These and other needs are met by the present invention which provides a profile system for measuring a profile of the strip of material produced in a reversing mill in which a direction of travel of the strip is reversible. The system comprises a single thickness gauge that measures the thickness of the strip and generates thickness signals. The moving device is coupled to the gauge and controllably moves the gauge transversely to the strip such that the gauge measures the thickness of the strip at different points across a width of the strip in one pass of the strip through the gauge. The gauge is maintained in the stationary position in another pass of the strip through the gauge such that the gauge measures the thickness of the strip at different points along a longitudinal line of the strip. Means are provided for interpreting measurements of the thickness of the strip at different points into profile data. This means for interpreting is connected to the gauge to receive the thickness signals.
The above-stated needs are also met by the present invention which provides a method of producing profile data of the strip of material with a single gauge and comprises passing the strip past the gauge and moving the gauge transversely relative to the strip as the strip is passed past the gauge. The thickness of the strip is measured at various points of the strip and various points of the strip across the width of the strip as the strip is passed past the gauge. A first set of signals are generated indicating the thickness measurements of the strip across the width of the strip. The strip is again passed past the gauge and the gauge is maintained in the stationary position as the strip again passes. The thickness of the strip is measured at various points of the strip along the longitudinal line of the strip as the strip is passed past the gauge. A second set of signals is generated indicating the thickness measurement of the strip along the longitudinal line. Profile data is generated from the first and second set of signals.
By taking advantage of the multiple passes through the mill of the strip of material, the present invention provides a system which uses a single gauge that is either stationary or moved transversely relative to the strip during the multiple passes of the strip through the mill. This allows only a single gauge to be used to perform in a punctual manner the two measurements needed to provide a profile, rather than the two gauges that have typically been used in known systems.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.